I personally feel that this is one of the best rushes available to any side. It is ready very fast (a true rush), it rewards good micro control, it is very dangerous especially if your opponent has not scouted correctly and has not prepared appropriate counters.
It is also surprisingly versatile.
Has a 'true' rush, the only downside is that because you are using your starting money towards the rush, your economy will be very slow (especially on maps with no Tiberium spikes), and you will be without a War factory for most of the early part of the game.
Unlike the RIG rush, this rush is useful on any map, although your opponent will obviously have more time to prepare a counter on a larger map.
- Build a power plant, and once it is placed build a Vulcan tower, which you will sell, and then send the Minigunner into the direction of your enemies base.
- Build a Barracks has soon has possible, build a single Minigunner squad and send it into the direction of your enemies base. If there are any safe Tiberium spikes, build engineer\s to capture them (the extra income is vital for rushes), then build a few more Mingunners, for scouting and if applicable on the map, garrisoning structures. Queue up between 7-10 Missile squads as well (these are going to be used for the rush, so keep them inside your base).
- Build a Refinery and place it, then immediately build a Command Post.
- Once you have placed the Command Post, immediately build a Orca Pad. If you are building 7 or 8 Missile squads, you can consider upgrading your lone Power plant (you need for the upgrade to be finished before the Orca Pad is ready to be placed).
- Place the Orca Pad, then sell the Command Post. You should have around 7 or 8 Missile squads by now (more if you used 2 Barracks), so with the money you have from selling the Command Post and the Barracks, select all the Missile squads (double click on one of them), and then use the 'Call for Transport' ability while they all selected (Ctrl+A).
- Select one of the descending BlackHawks and press the 'W' key to select all of the other BlackHawks, give them a Ctrl group number.
- Once the Missile squads have all been picked up, move out straight away. If you have correctly scouted, use the information to your advantage (for example approaching on a flank).
- At this point while you can sell the Orca Pad, consider keeping it. You can use the Magnetic mine drop support power to further disrupt the enemies Harvesters. Also you can consider building Orcas a little later on.
- Attack the enemy Harvesters. If your opponent had scouted you and discovered that you were going to do this rush, they will already have some anti-air ready. Use the speed and manoeuvrability of the BlackHawk to dodge enemy fire while attacking their Harvesters. If your enemy have built vehicle AA, then you might consider destroying them if possible, but the focus of this rush is to destroy has many harvesters has possible.
- It is very difficult for your opponent to prevent you from destroying at least one Harvester. If you are good at micro, you can pick out individual BlackHawks that are low on health and attempt to drop off the Missile squad inside before the BlackHawk is destroyed (remember because this is an economy rush, it is preferable that you lose some units to destroy a couple more Harvesters, rather than retreating). If you kept the Orca Pad up, and you do retreat, obviously you will be able to heal any damaged aircraft.
If you go for 10 Missile squads, consider using 2 Barracks instead of 1. This is so they will be ready in time for when the Orca Pad is placed (you will struggle to have 10 Missile squads built if you have to capture any spikes). Also do not get the Power plant upgrade, you will need the money for the BlackHawks (you will need $2000 to pick up all 10 squads).
Once again it is surprising how easily the 'slow' GDI can put the other sides on the back-foot. The BlackHawks are faster than even the Nod bikes (and cost the same, a Missile squad + a BlackHawk cost $600). Also you have the benefit of flying (i.e. going over water, cliffs, mountain ranges etc).
Because of how effective this rush is, your opponent will eventually be wary of it. If they see you building Missile squads they will be suspicious. If they see the Missile Squads and the Command Post, they will know what's coming (early Command Post always means that GDI is going to aerial rush).
Good early anti-scouting can certainly help, but also consider way-pointing your Missile squads from your Barracks to the rear of your base. Because of the speed of the BlackHawk, there is no need for the Missile squads to be at the front of your base, where they will be more easily seen!
Harassment variants
What is great about this rush is that you switch things up, unlike the RIG rush.
For example instead of going for a higher number of Missile squads, build only 5, and build a couple of engineers has well. Once you are at the point were it is time to call the BlackHawks, call the transports for the entire group (Missile squad and engineers). Give the Missile squad BlackHawks their own Ctrl group, and then give each individual engineer BlackHawk a unique Ctrl group.
What you are going to do is send the Missile BlackHawks to harass your opponent. Your goal is to draw enemy units towards them, and provide a distraction. While this is happening send the engineer BlackHawks along the edge of the map, and eventually over an important enemy structure (so Construction Yard and War factory\Refinery). Drop the engineers off and attempt to capture the structures (while your enemy is still distracted!). It does not matter if they sell (Refinery or War Factory, obviously they will pack the Construction Yard into an MCV), this is still a good result!
Also if you want, you can include some Minigunner squad BlackHawks to kill any ground based Missile\Rocket squads.
Counter
Scouting is vital in order to correctly prepare. Even if you know it is coming, it is still very difficult to defend against (like all very good rushes).
If you are GDI the best counter is... BlackHawks with Missile squads inside! Seriously!
However if you were not going for that build, then build a lot of Missile squads, and defend your harvesting area. Be prepared has a skilled rusher will start attacking structure in different parts of your base, in an attempt to get you to leave the harvesting area, so they can destroy your harvesters!
While vehicle counters are not recommended (too easy for the Missile squads to destroy, because they do not miss them, unlike when they try to hit infantry), if you can get a good group (minimum of 6, preferably 10) of Hummers, you will certainly catch the attention of a BlackHawk rusher, and they will be forced into evasive manoeuvres.
Similar with Nod. preferably Rocket Squads in mass, if not consider mass Buggy spam (at least 7).
The Scrin have it very tough. They have no choice but to use vehicles (unless you try a risky counter and go to tier 2 so you can build Plasma Batteries, although if you do, make sure your Power plant is nearby the Plasma Batteries, the rusher will be attempting to destroy your Power to power down your defences).
Build a few Gun Walkers (do not send them to defend one at a time, they will get picked off).
Because you have to use vehicles, the rusher can (and will) move around trying to get you away from the harvesting area.
In this case, it really helps the Scrin if it is a larger map (more time to mass Gun Walkers).
Conclusion
What is great about this rush, is that it can put both Nod and the Scrin on the defensive early in a match. It also has good potential variety, and finally it rewards micro.
